Process of manufacturing fusible dental fillings, inlays, and crowns.



. No. 856,034. A PATENTED JUNE 4, 1907.

- J. N. GROUSE.

PROCESS OF MANUFACTURING FUSIBLE DENTAL FILLINGS, INLAYS;

AND caowns. APPLICATION FILED MAR. 14, 190B.

. and'zinc oxid, both of which are UNITED STATES PA NT o FIoE- JOHN N.cRoUsE, OFCHIOAGO, ILLINOIS. PROCESS or MANUFACTURING rususuz DENTALnumes, INLAYS, AND crowns.

Specification of Letters Patent.

Patented June 4, 1907.

Application filed March 14,1906. serialllo- 306,081.

To all whom it may concern:

Be it known that I, JOHN N. CROUSE, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain-new and useful Improvements in Processes ofManufacturing Fusible Dental Fillings,-Inlays, and Crowns, of which thefollowing is a specification.

My invention relates to improvementsin fillings, inlays and crowns forteeth, and has reference more particularly to a new method or process ofmanufacturing a composite substance adapted for the above-named uses.

In the matter of restoration materials for teeth, a variety ofconsiderations have to be taken into account, principal among which are.(a) strength; (1)) durability; (0) appearance; (d) molding quality; (e)glazing efiect; and (f) freedom from shrinkage. Ordinary orcelain, atpresent extensively employed or these purposes, is largel deficient instrength; and; while rating hlgh as regards appearance, is often injuredb reason'of the cement showing through. llany of the amalgams now inuserate high as regards strength and durability, but are clearly deficientin respect to appearance, being dark and entirely out of color harmonywith the natural tooth.

The object of my invention is to produce a composite substancethat shallcombine in as perfect a degree as possible all of the various desiderataabove specified; and such a'material I have discovered, as a result ofnumerone and long continued experiments, in a composition having as itsessentials feldspar,

silex, and one or more metal oxids; the oxids yielding the best resultsbeing tin oxid referably s regards employed in the composition.

ative amounts of these in edients I the re have tested several formulas,all-of whichgive good results, and some being superior to others in oneor more of the desirable quali ties above enumerated, according to therelative amounts of the different ingredients employed. i

. Without attempting to name all 'of the formulas which may be employedadvantageously and within the purview of the invention, I will defineseveral, it being understood that the proportionate parts named are.approximate only and not necessarily absolute. Formula 1.. Feldspar 96;silex 13; tin oxid 100; zinc oxid 50.

Formula 2. Feldspar 96 silex 13 tin oxid 100; zinc oxid 100.

Formula 3. Feldspar 96 silex 13 ;tin oxid 200; zinc oxid 100.

Formula 4. Feldspar 96; silex '13 tin oxid 400; zinc oxid 100.

Formula 5. Feldspar 100; silex 13; tin oxid 50; zinc oxid 50. V

The amounts above given express the rela-. tive quantities by Wei ht ofthe edients.

It will be observed t at in all of t e formulas the amounts of feldsparand silex are substantially constant; the variations being in therelative amounts of the metal oxids. Of the oxids named the tin oxid isof the greater importance, as it constitutes the principalstrength-giving element, besides enhancing the glazing efiect, andlimiting the shrinkage that occurs upon baking or fusing.

Referring now to the manner inwhich the ingredients are united andformed into a filling, inlay or crown, it may be stated that at theoutset each of the ingredients, excepting the feldspar, ispreferablysubjected to a heat ranging from 2200 to 2800 Fahrenheit. Theingredients are then finely ground and thoroughly mixed together; The.dry comosition thus formed is then mixed with a iquid comprisingphosphoric acid and water. Preferably a liquid mixture of phosphoricacid of specific gravity 80 with an equal weight of Water is employed;and any suitable coloring may be added if desired, among the coloringmatters being mentioned iron phosphate, red oxid of iron, black oxid ofiron, lead dioxid, cobalt oxid nickel oxid, platinum black, black copperoxid and red copper oxid; one or more of these being added according tothe tint or colorefiect desired. The material is mixed to a plasticform, and, 'the cavity ha'ving previously been coated with some oilysubstance, it is molded into the cavity of the natural'tooth, or of areproduction thereof, after which itis fused or enameled by baking. Thislatter operation produces a certain shrinking or contraction, makin itnecessary to refit the filling or inlay to t e cavity, which is done byapplying to the cavity-contacting surface thereof a thin coating of theoriginal or simi lar plastic material, and again impressingv the fillingor ity, removing it before the coating hardens, trimming off the surplusand again baking it but not to the fusing or' enamehng point.-

inlay thus coated into the cav- This leaves a sufficiently roughcavity-contacting surface on the filling or inlay to suitably cooperatewith the cement by which paratively high heating point, necessitatingperature when the use of an oven capable of affording a sufficientlyhigh heat to effect such fusin I have discovered that the material willbe rendered fusible at a considerably lower temmixed with a flux; andaccordingly where the capacity of the oven is limite or, for otherreasons, a very high bakin temperature is undesirable or impossibleflmix with the composition a suitable flux and use the resultingcomposition in the manner already set forth. A flux composed of fluoridof sodium, and fluorid of aluminium, mixed in the proportions of 25.2parts by weight of the former to 17.8 parts by weight of the lattergives goodresults.

In order to make clearer the uses-and appli: cations of my novel dentalmaterial, I have illustrated the same by the accompanying drawing, inwhich,

Figure 1 represents a section of'a jaw containing a molar prepared forfilling, or an artificial reproduction thereof; Fi 2 represents thefilling or inlay detache as molded and ready to be cemented in thetooth; Fi 3 is a view similar to Fig. 1 showing the filling or inlaycemented in place in the molar; and Figs. 4, 5 and 6 are viewscorresponding with Figs. 1, 2'and 3, respectively, but showing my noveldental material employed for the purpose of a crown.

Referring to the drawings, 10 ma *desig nate a sectlon of the jaw or anarti cial re.

production thereof, and 11 a molar therein containin a large excavatedcavity 12 prepared folllin 13 designates aninlay'or filling fitted andprepared as hereinabove describe the same being shownas applied to thetooth in Fig. 3.

.anchoring pins on the base of the crown.

In Fi s. 4 and 6, 14 designates a root, or an artificial reproductionthereof, suitably prepared to receive a crown; 15 designating the pulpcavities therein which may receive 16 designates the crown itself, madeof the materials andin the manner above described and equipped withanchoring pins 17 adapted to fit the holes 15. Fig. 6 shows the crownsecured in place on the root. The anchoring pins may, of course; beomitted.

I claim:

- 1. A process of manufacturing dental filling and crowning materialwhich consists in mixing ground eldspar, silex, and one or more metaloxids; reducing them to a plastic condition by the addition ofphosphoric acid and water; moldin the paste thus formed to the tooth;and then baking and fusing the same.

2. A process of manufacturin dental filling and crowning material, whic1 consists in mixing ground'feldspar, silex, and one or more metaloxids; reducing them to a plastic condition by the addition ofphosphoric acid and water; molding the paste "thus formed to the tooth;then baking and fusing the same; then applyin a thin coating of the sameplastic materia then refitting the coated filling to the tooth; andfinally rebakin the same to less than a fusing heat.

3. .5 process of manufacturin dental filling and crowning material, whicconslsts-in preliminarily subjecting silex and one or more metal oxidsto a temperature of from 2200 to 2800 Fahrenheit; then mixing the samewith ground feldspar; then reducing the mixture to a plastic conditionby the addition of phosphoric acid and water; then molding the mixtureto the tooth; and then baking and fusing the same.

JOHN N. OROUSE.

Witnesses:

SAMUEL N. POND, F. MoCRnA.

